One of the important things to learn about stats in this game is that the damage formula involves truncated numbers. As a result of these truncated numbers, it introduces stat tiers before seeing an increase in results. For example a value of 2300 and 2301 may have the same damage value. However if 2301 reaches the next stat tier, you may see a damage increase. The main goal for stat is too efficiently reach as many stat tiers for each stat type (Crit, Det, Direct Hit, Spell Speed, Etc.) for the relevant job. Of course, certain stats may be considered more valuable for different jobs.

Crit increases damage for every 17 points over base value. Direct Hit increases damage for every 6 points. Det increases damage for every 26 points.

If you want to see where the stat intervals are for each stat type, you can check out this website: http://theoryjerks.akhmorning.com/stats/crit/
There are BiS gear lists that the community created if you do not want to think too much about what to meld.